body {
        height: 90vh;
        /*background: linear-gradient(#141e30, #243b55);*/
        display: flex;
        font-size: 16px;
        color: #3F51B5;
		font-family: "Lato", sans-serif;
    }

.sidebar {
  margin: -8px;
  padding: 0;
  width: 380px;
  background-color: #141e30;
  position: fixed;
  height: 100%;
  overflow: auto;
}

.sidebar a {
  display: block;
  font-size: 18px;
  color: #7e5757;
  padding: 16px;
  text-decoration: none;
}

.sidebar a.active {
  background-color: #4CAF50;
  color: white;
}

.sidebar a:hover:not(.active) {
  background-color: #555;
  color: white;
}

div.content {
  margin-left: 200px;
  padding: 1px 16px;
  height: 1000px;
}

@media screen and (max-width: 700px) {
  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
  }
  .sidebar a {float: left;}
  div.content {margin-left: 0;}
}

@media screen and (max-width: 400px) {
  .sidebar a {
    text-align: center;
    float: none;
  }
}

p{
	text-align: center;
	padding-top:30px;
}

.main {
  margin-left: 380px; /* 与 sidenav 的宽度相同 */
  padding: 0 10px;
}